/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
* add the following below this CDDL HEADER, with the fields enclosed
* by brackets "[]" replaced with your own identifying information:
* Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
*
* Copyright 2008 Sun Microsystems, Inc.
* Portions Copyright 2011-2013 ForgeRock AS
*/
package org.opends.server.replication.protocol;
import org.opends.server.api.DirectoryThread;
import static org.opends.server.loggers.debug.DebugLogger.*;
import org.opends.server.loggers.debug.DebugTracer;
import org.opends.server.types.DebugLogLevel;
import java.io.IOException;
/**
* This thread publishes a heartbeat message on a given protocol session at
* regular intervals when there are no other replication messages being
* published.
*/
public class HeartbeatThread extends DirectoryThread
{
/**
* The tracer object for the debug logger.
*/
private static final DebugTracer TRACER = getTracer();
/**
* For test purposes only to simulate loss of heartbeats.
*/
private static volatile boolean heartbeatsDisabled = false;
/**
* The session on which heartbeats are to be sent.
*/
private final Session session;
/**
* The time in milliseconds between heartbeats.
*/
private final long heartbeatInterval;
/**
* Set this to stop the thread.
*/
private volatile boolean shutdown = false;
private final Object shutdownLock = new Object();
/**
* Create a heartbeat thread.
* @param threadName The name of the heartbeat thread.
* @param session The session on which heartbeats are to be sent.
* @param heartbeatInterval The desired interval between heartbeats in
* milliseconds.
*/
public HeartbeatThread(String threadName, Session session,
long heartbeatInterval)
{
super(threadName);
this.session = session;
this.heartbeatInterval = heartbeatInterval;
}
/**
* {@inheritDoc}
*/
@Override
public void run()
{
try
{
if (debugEnabled())
{
TRACER.debugInfo("Heartbeat thread is starting, interval is %d",
heartbeatInterval);
}
HeartbeatMsg heartbeatMessage = new HeartbeatMsg();
while (!shutdown)
{
long now = System.currentTimeMillis();
if (debugEnabled())
{
TRACER.debugVerbose("Heartbeat thread awoke at %d, last message " +
"was sent at %d", now, session.getLastPublishTime());
}
if (now > session.getLastPublishTime() + heartbeatInterval)
{
if (!heartbeatsDisabled)
{
if (debugEnabled())
{
TRACER.debugVerbose("Heartbeat sent at %d", now);
}
session.publish(heartbeatMessage);
}
}
long sleepTime = session.getLastPublishTime() +
heartbeatInterval - now;
if (sleepTime <= 0)
{
sleepTime = heartbeatInterval;
}
if (debugEnabled())
{
TRACER.debugVerbose("Heartbeat thread sleeping for %d", sleepTime);
}
synchronized (shutdownLock)
{
if (!shutdown)
{
try
{
shutdownLock.wait(sleepTime);
}
catch (InterruptedException e)
{
// Server shutdown monitor may interrupt slow threads.
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
shutdown = true;
}
}
}
}
}
catch (IOException e)
{
if (debugEnabled())
{
TRACER.debugInfo("Heartbeat thread could not send a heartbeat.");
}
// This will be caught in another thread.
}
finally
{
if (debugEnabled())
{
TRACER.debugInfo("Heartbeat thread is exiting.");
}
}
}
/**
* Call this method to stop the thread.
* This method is blocking until the thread has stopped.
*/
public void shutdown()
{
synchronized (shutdownLock)
{
shutdown = true;
shutdownLock.notifyAll();
if (debugEnabled())
{
TRACER.debugInfo("Going to notify Heartbeat thread.");
}
}
if (debugEnabled())
{
TRACER.debugInfo("Returning from Heartbeat shutdown.");
}
}
/**
* For testing purposes only to simulate loss of heartbeats.
* @param heartbeatsDisabled Set true to prevent heartbeats from being sent.
*/
public static void setHeartbeatsDisabled(boolean heartbeatsDisabled)
{
HeartbeatThread.heartbeatsDisabled = heartbeatsDisabled;
}
}